The utility model provides a driving mechanism for a paper feeding shaft of a printer. The driving mechanism comprises a cross beam, the paper feeding shaft, a paper feeding shaft support frame, an end support frame, a motor mounting seat and a driving motor, the number of the paper feeding shaft supporting frames is at least two, the paper feeding shaft supporting frames are installed on the cross beam, shaft sleeves are installed at the positions, matched with the paper feeding shaft supporting frames, of a shaft body of the paper feeding shaft, and the shaft sleeves are installed on the paper feeding shaft supporting frames through bearings and bearing pedestals; the end supporting frame is arranged at one end of the cross beam, an end bearing seat is arranged on the inner side of the end supporting frame, a via hole is formed in the position, corresponding to the axis of the end bearing seat, of the end supporting frame, and one end of the paper feeding shaft penetrates through the via hole; a motor mounting seat is arranged on the outer side of the end supporting frame, the driving motor is mounted on the motor mounting seat, and a transmission shaft is coaxially and directly connected with one end of the paper feeding shaft. The driving mechanism for the paper feeding shaft of the printer has the advantages of stronger power, higher stability and higher movement precision.